Acute flaccid myelitis (AFM) tends to start with limb weakness, sometimes accompanied by fever, headache, and back or neck pain, and can quickly progress over a number of days, leading to permanent paralysis or respiratory failure. It affects the nervous system, specifically gray matter at the center of the spinal cord, causing weakness of the muscles and reflexes. The uncommon disease has seen peaks in the US between August and November every two years since 2014, so the CDC has released an updated Vital Signs report to alert doctors to a possible outbreak this year.
The last peak, in 2018, saw the most cases so far with 238 people taken ill across 42 states. Of these cases, 94 percent were in children. Ninety-eight percent of patients diagnosed with the condition required hospital treatment, with 54 percent being admitted to intensive care and one in four requiring mechanical ventilation. The disease has seen rises in cases every two years since the CDC began surveillance for AFM following a peak of 120 cases in 2014.
The disease is believed to be caused by enteroviruses – a virus transmitted through the intestine – particularly enterovirus-D68 (EV-D68). Enteroviruses are usually mild, but can cause serious illness when they infect the central nervous system, as is the case with AFM. It's hoped that social distancing measures put in place to combat Covid-19 could also combat the spread of enteroviruses and result in fewer cases of AFM, though it may also make it more difficult for the health care system to diagnose and treat the condition.
The CDC has warned that parents and doctors should look out for signs of the disease and to suspect AFM in any patients with sudden limb weakness, particularly between August and November. Recent respiratory illnesses, neck and back pain, and other neurological symptoms are also big indicators of the disease. They urge pediatricians and emergency departments to be prepared to quickly recognize symptoms of AFM, and immediately hospitalize any patients with the disease.
Parents have been advised to seek immediate medical attention if they suspect their child has the condition, even in areas where Covid-19 cases are prevalent. Currently, there is no proven treatment or prevention method for the disease.
“Recognition and early diagnosis are critical," CDC Director Dr Robert Redfield said in a statement. "Public health partners have strengthened early disease detection systems, a vital step toward rapid treatment and rehabilitation for children with AFM.”
As of July 31, there have been 16 confirmed cases, and 38 patients under investigation for the disease, this year so far. The CDC urges parents and clinicians to remain vigilant for AFM from now until the end of November.